The present invention relates to the polymerization of olefins. In another aspect this invention relates to novel catalysts useful for the polymerization of olefins.
In another aspect this invention relates to novel compositions of matter comprising crystalline magnesium dihalide/electron donor adducts and a method of making same.
In commonly owned U.S. Pat. No. 4,394,291, there is disclosed a number of new high activity polymerization catalysts. The disclosure of said application is hereby incorporated by reference. One of those catalysts types disclosed was prepared by reacting reactants comprising (a) a magnesium dihalide, (b) a benzoic acid ester, and (c) a titanium compound, such as an alkoxytitanium compound, to produce a first catalyst component, then reacting that component with a second catalyst component comprising a precipitating agent, and then reacting the resulting solid product with halogenating agent, such TiCl.sub.4.
South African Pat. No. 230/84 reveals that the activity of such catalysts can be affected by the amount of water associated with the magnesium dihalide. The activity obtained with catalysts prepared from magnesium dihalide containing less than 0.5 moles of H.sub.2 O per mole of magnesium dihalide were inferior to catalysts prepared using magnesium dihalides containing higher levels of water.
The present application is directed to the discovery that the activity of such catalysts can also be improved by adding specified amounts of alkanol to the magnesium dihalide.